爬虫6：pyquery库
强大又灵活的网页解析库，如果觉得正则写起来太麻烦，BeautifulSoup语法太难记，而你又熟悉jQuery的语法，那么用PyQuery就是最佳选择
一. 初始化
1. 字符串初始化
html = '''
<div>
<ul>
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
</ul>
</div>
''' from pyquery import PyQuery as pq
doc = pq(html)
print(doc('li'))
输出结果：
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
2. URL初始化，就是提取URL的源码
from pyquery import PyQuery as pq
doc = pq(url='http://www.baidu.com')
print(doc('head'))
输出结果：
<head><meta http-equiv="content-type" content="text/html;charset=utf-8"/><meta http-equiv="X-UA-Compatible" content="IE=Edge"/><meta content="always" name="referrer"/><link rel="stylesheet" type="text/css" href="http://s1.bdstatic.com/r/www/cache/bdorz/baidu.min.css"/><title>ç¾åº¦ä¸ä¸ï¼ä½ å°±ç¥é</title></head>
3. 文件初始化，提取文件中的源码
from pyquery import PyQuery as pq
doc = pq(filename='demo.html') //读取文本文件
print(doc('li'))
输出结果
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
二. 基本CSS选择器
html = '''
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
</ul>
</div>
'''
from pyquery import PyQuery as pq
doc = pq(html)
print(doc('#container .list li')) //后续的选择器不需要一定是父子关系
输出结果
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
1. 查找元素
1.1 子元素
使用find方法来查找子元素，比较常用
html = '''
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
</ul>
</div>
'''
from pyquery import PyQuery as pq
doc = pq(html)
items = doc('.list')
print(type(items))
print(items)
lis = items.find('li')
print(type(lis))
print(lis)
输出结果：
<class 'pyquery.pyquery.PyQuery'>
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
</ul> <class 'pyquery.pyquery.PyQuery'>
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
使用children查找直接子元素
lis = items.children()
print(type(lis))
print(lis)
输出结果：
<class 'pyquery.pyquery.PyQuery'>
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
在children中加入参数后，会进一步精细查找，相当于层级查找
lis = items.children('.active')
print(lis)
//输出信息
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
1.2 父元素
1.2.1：使用parent来查找父元素
html = '''
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
</ul>
</div>
'''
from pyquery import PyQuery as pq
doc = pq(html)
items = doc('.list')
container = items.parent()
print(type(container))
print(container)
输出结果
<class 'pyquery.pyquery.PyQuery'>
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
</ul>
</div>
1.2.2：使用parents查找所有祖先节点
html = '''
<div class="wrap">
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
</ul>
</div>
</div>
'''
from pyquery import PyQuery as pq
doc = pq(html)
items = doc('.list')
parents = items.parents()
print(type(parents))
print(parents)
输出信息
<class 'pyquery.pyquery.PyQuery'>
<div class="wrap">
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
</ul>
</div>
</div><div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
</ul>
</div>
1.2.3：parents加上参数精细查找
parent = items.parents('.wrap')
print(parent)
输出结果：
<div class="wrap">
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
</ul>
</div>
</div>
1.3 兄弟元素
1.3.1：注意：item-0.active之间没有空格，而是用"."，表示与的关系
html = '''
<div class="wrap">
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
</ul>
</div>
</div>
'''
from pyquery import PyQuery as pq
doc = pq(html)
li = doc('.list .item-0.active')
print(li.siblings())
输出结果
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0">first item</li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
1.3.2：在兄弟元素中加上参数进一步筛选
html = '''
<div class="wrap">
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
</ul>
</div>
</div>
'''
from pyquery import PyQuery as pq
doc = pq(html)
li = doc('.list .item-0.active')
print(li.siblings('.active'))
输出：
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
2. 遍历
2.1 单个元素
2.1.1：基本用法
html = '''
<div class="wrap">
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
</ul>
</div>
</div>
'''
from pyquery import PyQuery as pq
doc = pq(html)
li = doc('.item-0.active')
print(li)
输出：
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
2.1.2：遍历使用items方法
html = '''
<div class="wrap">
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
</ul>
</div>
</div>
'''
from pyquery import PyQuery as pq
doc = pq(html)
lis = doc('li').items() #加上items()可以输出网页内容，否则只会输出类似<Element li at 0x7f032b4d8248>的元素
print(type(lis))
for li in lis:
print(li)
输出信息
<class 'generator'>
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
3. 获取信息
3.1 获取属性，使用attr()方法
html = '''
<div class="wrap">
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
</ul>
</div>
</div>
'''
from pyquery import PyQuery as pq
doc = pq(html)
a = doc('.item-0.active a') #不需要按层级查找，这里就不需要写div，ul标签
print(a)
print(a.attr('href')) #方法1
print(a.attr.href) #方法2
输出：
<a href="link3.html"><span class="bold">third item</span></a>
link3.html
link3.html
3.2 获取文本
html = '''
<div class="wrap">
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
</ul>
</div>
</div>
'''
from pyquery import PyQuery as pq
doc = pq(html)
a = doc('.item-0.active a')
print(a)
print(a.text())
输出信息：
<a href="link3.html"><span class="bold">third item</span></a>
third item
3.3 获取HTML内容，这里就是获取<a>标签中的内容，如果有多个a标签，只会获得第一个a标签内容
html = '''
<div class="wrap">
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
</ul>
</div>
</div>
'''
from pyquery import PyQuery as pq
doc = pq(html)
li = doc('.item-0.active')
print(li)
print(li.html())
输出结果：
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<a href="link3.html"><span class="bold">third item</span></a>
4. DOM操作
4.1 addClass、removeClass
html = '''
<div class="wrap">
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
</ul>
</div>
</div>
'''
from pyquery import PyQuery as pq
doc = pq(html)
li = doc('.item-0.active')
print(li)
li.removeClass('active')
print(li)
li.addClass('active')
print(li)
输出结果：
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-0"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
4.2 attr、css
html = '''
<div class="wrap">
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
</ul>
</div>
</div>
'''
from pyquery import PyQuery as pq
doc = pq(html)
li = doc('.item-0.active')
print(li)
li.attr('name', 'link') #若原先不存在name属性，那么会新增name=link，如果原先有name属性，则会修改为新值
print(li)
li.css('font-size', '14px') #新增一个style属性
print(li)
输出结果：
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-0 active" name="link"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-0 active" name="link" style="font-size: 14px"><a href="link3.html"><span class="bold">third item</span></a></li>
4.3 remove
html = '''
<div class="wrap">
Hello, World
<p>This is a paragraph.</p>
</div>
'''
from pyquery import PyQuery as pq
doc = pq(html)
wrap = doc('.wrap')
print(wrap.text())
wrap.find('p').remove() #移出p标签
print(wrap.text())
输出信息：
Hello, World This is a paragraph.
Hello, World
其他DOM方法
伪类选择器
html = '''
<div class="wrap">
<div id="container">
<ul class="list">
<li class="item-0">first item</li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-0 active"><a href="link3.html"><span class="bold">third item</span></a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
</ul>
</div>
</div>
'''
from pyquery import PyQuery as pq
doc = pq(html)
li = doc('li:first-child') #获取第一个li标签
print(li)
li = doc('li:last-child')
print(li)
li = doc('li:nth-child(2)') #获取第2个li标签
print(li)
li = doc('li:gt(2)') #大于2的li标签
print(li)
li = doc('li:nth-child(2n)') #偶数的li标签
print(li)
li = doc('li:contains(second)') #包含second文本的li标签
print(li)
输出信息：
<li class="item-0">first item</li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-0"><a href="link5.html">fifth item</a></li>
<li class="item-1"><a href="link2.html">second item</a></li>
<li class="item-1 active"><a href="link4.html">fourth item</a></li>
<li class="item-1"><a href="link2.html">second item</a></li>
更多CSS选择器可以查看 http://www.w3school.com.cn/css/index.asp
官方文档
爬虫6：pyquery库的更多相关文章
- 爬虫之pyquery库
官方文档:https://pyquery.readthedocs.io/en/latest/ PyQuery是一个强大又灵活的网页解析库.如果你觉得正则写起来太麻烦.BeautifulSoup语法太难 ...
- Python爬虫之pyquery库的基本使用
# 字符串初始化 html = ''' <div> <ul> <li class = "item-0">first item</li> ...
- python爬虫从入门到放弃（七）之 PyQuery库的使用
PyQuery库也是一个非常强大又灵活的网页解析库,如果你有前端开发经验的,都应该接触过jQuery,那么PyQuery就是你非常绝佳的选择,PyQuery 是 Python 仿照 jQuery 的严 ...
- 爬虫常用库之pyquery 库
pyquery库是jQuery的Python实现,可以用于解析HTML网页内容,我个人写过的一些抓取网页数据的脚本就是用它来解析html获取数据的.他的官方文档地址是:http://packages. ...
- Python爬虫-- PyQuery库
PyQuery库 PyQuery库也是一个非常强大又灵活的网页解析库,PyQuery 是 Python 仿照 jQuery 的严格实现.语法与 jQuery 几乎完全相同,所以不用再去费心去记一些奇怪 ...
- PYTHON 爬虫笔记六:PyQuery库基础用法
知识点一:PyQuery库详解及其基本使用 初始化 字符串初始化 html = ''' <div> <ul> <li class="item-0"&g ...
- 第四节：Web爬虫之pyquery解析库
PyQuery库也是一个非常强大又灵活的网页解析库,如果你有前端开发经验的,都应该接触过jQuery,那么PyQuery就是你非常绝佳的选择,PyQuery 是 Python 仿照 jQuery 的严 ...
- python之爬虫（九）PyQuery库的使用
PyQuery库也是一个非常强大又灵活的网页解析库,如果你有前端开发经验的,都应该接触过jQuery,那么PyQuery就是你非常绝佳的选择,PyQuery 是 Python 仿照 jQuery 的严 ...
- Python3 网络爬虫（请求库的安装）
Python3 网络爬虫(请求库的安装) 爬虫可以简单分为几步:抓取页面,分析页面和存储数据 在页面爬取的过程中我们需要模拟浏览器向服务器发送请求,所以需要用到一些python库来实现HTTP的请求操 ...
- 爬虫之PyQuery的base了解
爬虫之PyQuery的base了解 pyquery库是jQuery的Python实现,能够以jQuery的语法来操作解析 HTML 文档,易用性和解析速度都很好,和它差不多的还有BeautifulSo ...
随机推荐
- Grapher
[Grapher] You use Grapher to visualize and analyze implicit and explicit equations. You can graph eq ...
- 015年传智播客JavaEE 第168期就业班视频教程15-模块规范化
注册功能最起码得有个用户名和密码吧. bigint相当于Java里面的Long.Long型最大的那个数字是19位,我们这里是20位,绝对够用. userName长度预留20%,让它后期可扩展.6-12 ...
- Resolving multicopy duplications de novo using polyploid phasing 用多倍体相位法解决多拷贝复制的新问题
抽象.虽然单分子测序系统的兴起已经实现组装复杂地区的能力空前提高在基因组中,基因组中的长节段重复仍然是装配中具有挑战性的前沿. 分段重复同时具有丰富的基因并且倾向于大的结构重排,使得它们的序列的分辨率 ...
- [Selenium]计算坐标进行拖拽，重写dragAndDropOffset
//@author jzhang6 public void dragAndDropOffset(WebDriver driver,WebElement dragableEl, WebElement d ...
- linux 关键发行版及其关系图
- css控制两个表格的边线重合
控制两个表格的边线重合 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http:/ ...
- 矩阵乘法np.dot()及np.multiply()以及*
转载自 https://blog.csdn.net/u012609509/article/details/70230204 Python中的几种矩阵乘法 1. 同线性代数中矩阵乘法的定义: np.do ...
- oj1089-1096总结（输入输出练习）
//无限输出类 #include<stdio.h>int main(void){ int a,b; while((scanf("%d %d",&a,&b ...
- .NET平台机器学习资源汇总，有你想要的么？（转）
出处:http://www.cnblogs.com/asxinyu/p/4422050.html 阅读目录 1.开源综合类 2.开源.NET平台非综合类 3.其他资源与技术博客 4.我的100篇博客之 ...
- swoole1.8.0+版本异步redis安装(本实例为swoole1.8.10版本)详解
Swoole-1.8.0+版本增加了对异步Redis客户端的支持,基于redis官方提供的hiredis库实现.Swoole提供了__call魔术方法,来映射绝大部分Redis指令(本次安装实例为sw ...